SN74HC251PWR

Overview

The SN74HC251PWR is a data selector/multiplexer in the HC logic family, housed in a 16-pin TSSOP package. It features a wide operating voltage range of 2 V to 6 V and provides high-current 3-state outputs capable of driving up to 15 LSTTL loads. The device includes full binary decoding to select one of eight data sources, controlled by strobe inputs. Electrical characteristics include a typical propagation delay of 9 ns, low power consumption with a maximum ICC of 80 μA, and an output drive capability of ±6 mA at 5 V.

Feature Summary

• Features complementary true and inverted 3-state outputs for direct system bus interfacing
• Contains full binary decoding to select one of eight independent data sources
• Outputs are strobe-controlled via an enable input to manage bus line impedance

Applications

• Parallel-to-serial data conversion
• Data routing in bus-organized systems
• Address decoding applications

Procurement Notes

Verify the specific ordering suffix 'PWR' corresponds to the TSSOP-16 package and tape-and-reel carrier configuration. Confirm that the RoHS compliance status and moisture sensitivity level match the requirements for the intended assembly process. Ensure the lead finish meets solderability standards for the chosen mounting method.

Selection Notes

Select this component when a standard 8-to-1 multiplexer with tri-state output buffering is required within the HC logic family. It serves as the 3-state equivalent to the SN74HC151. Consider the 2 V to 6 V supply range and -40°C to 85°C operating temperature limits against system constraints. Evaluate the 16-pin TSSOP footprint availability against board space limitations.

Part Context

This part belongs to the SNx4HC251 series of data selectors manufactured by Texas Instruments. It is functionally compatible with other industry-standard 8-line multiplexers but offers specific 3-state output control. The device is designed for general-purpose digital logic applications requiring signal selection and bus isolation.

Replacement Considerations

SN74HC151DR: Identical functionality without 3-state outputs; requires external buffering if bus isolation is needed.

FAQ

How does the OE pin affect the output state?

When the Output Enable (OE) input is high, all outputs enter a high-impedance state. When OE is low, the selected data input is transmitted to the Y and W outputs.

What is the purpose of the complementary outputs?

The device provides both true (Y) and inverted (W) outputs simultaneously, allowing access to both logic states of the selected data source without additional inversion circuitry.